| ( | x | − | 6 | ) | ( | x | − | 2 | ) | ( | x | − | 7 | ) | + | 4 | ( | 18 | − | 5 | x | ) | = | 0 |
| Left side of the equation = | x | ( | x | − | 2 | ) | ( | x | − | 7 | ) | − | 6 | ( | x | − | 2 | ) | ( | x | − | 7 | ) | + | 4 | ( | 18 | − | 5 | x | ) |
| = | x | x | ( | x | − | 7 | ) | − | x | × | 2 | ( | x | − | 7 | ) | − | 6 | ( | x | − | 2 | ) | ( | x | − | 7 | ) | + | 4 | ( | 18 | − | 5 | x | ) |
| = | x | x | x | − | x | x | × | 7 | − | x | × | 2 | ( | x | − | 7 | ) | − | 6 | ( | x | − | 2 | ) | ( | x | − | 7 | ) |
| = | x | x | x | − | x | x | × | 7 | − | x | × | 2 | x | + | x | × | 2 | × | 7 |
| = | x | x | x | − | x | x | × | 7 | − | x | × | 2 | x | + | x | × | 14 | − | 6 |
| = | x | x | x | − | x | x | × | 7 | − | x | × | 2 | x | + | 14 | x | − | 6 |
| = | x | x | x | − | x | x | × | 7 | − | x | × | 2 | x | + | 14 | x | − | 6 |
| = | x | x | x | − | x | x | × | 7 | − | x | × | 2 | x | + | 14 | x | − | 6 |
| = | x | x | x | − | x | x | × | 7 | − | x | × | 2 | x | + | 14 | x | − | 6 |
| = | x | x | x | − | x | x | × | 7 | − | x | × | 2 | x | + | 56 | x | − | 6 |
| = | x | x | x | − | x | x | × | 7 | − | x | × | 2 | x | + | 56 | x | − | 6 |
| = | x | x | x | − | x | x | × | 7 | − | x | × | 2 | x | + | 56 | x | − | 6 |
| = | x | x | x | − | x | x | × | 7 | − | x | × | 2 | x | + | 68 | x | − | 6 |
| = | x | x | x | − | x | x | × | 7 | − | x | × | 2 | x | + | 68 | x | − | 6 |
| = | x | x | x | − | x | x | × | 7 | − | x | × | 2 | x | + | 68 | x | − | 6 |
| = | x | x | x | − | x | x | × | 7 | − | x | × | 2 | x | + | 48 | x | − | 6 |
| x | x | x | − | x | x | × | 7 | − | x | × | 2 | x | + | 48 | x | − | 6 | = | 0 |